[PR Title / Module Name]

PR #XXX Author: @username Date: YYYY-MM-DD

TL;DR: [One sentence summary]

Risk Map

🟢 safe src/utils.ts

🟡 worth a look src/auth.ts

🔴 needs attention src/payment.ts

Code Changes

      src/auth.ts
      +12 -3
    
  function verifyToken(token: string) {
-   return jwt.verify(token, SECRET);
+   const decoded = jwt.verify(token, SECRET);
+   if (!decoded.sub) throw new AuthError('Invalid token');
+   return decoded;
  }

Behavior Change

Before

Token without 'sub' claim accepted
No validation on decoded payload

After

Token must have 'sub' claim
Explicit AuthError on invalid token

Request Path

[Browser]

→

[Load Balancer]

→

[API /api/session]

→

[verifyToken]

→

[SessionStore]

Call Stack Walkthrough

1 src/app/providers/AuthProvider.tsx:22-48

On mount, the React provider issues GET /api/session to check auth status.

show source

useEffect(() => {
  fetch('/api/session')
    .then(r => r.json())
    .then(setUser);
}, []);

2 src/middleware/auth.ts:14-31 ⚠️ TRUST BOUNDARY

This is the trust boundary. verifyToken reads the signed cookie and validates it.

show source

function verifyToken(token: string) {
  const decoded = jwt.verify(token, SECRET);
  if (!decoded.sub) throw new AuthError('Invalid token');
  return decoded;
}

Trust Boundary

⚠️ Trust Boundary

Everything below verifyToken is trusted. Everything above it is not.

This is where the JWT token is validated against the secret. Any tampering here compromises the entire session.